I have a BitmapSource loaded from a byte array this way:
BitmapSource bitmap = null;
using (var stream = new MemoryStream(bytes))
{
var decoder = new JpegBitmapDecoder(stream, BitmapCreateOptions.None, BitmapCacheOption.None);
bitmap = decoder.Frames[0];
stream.Flush();
}
return bitmap;
When I'm trying to write this as an JPEG to disk, it only throws an error:
Any ideas here? Other ways of writing the image to disk?
Related
I have two functions: one to convert from image to byte and other to convert from byte to bitmapImage.
So, when I open the window with that images, I convert from byte to bitmapImage and it works great, but when I close and open it again it just keeps on memory and if I continue to do that time and time again it just throws an exception Out Of Memory exception
Image to byte->
private byte[] ConvertImageToBinary(Image img)
{
using (MemoryStream ss = new MemoryStream())
{
img.Save(ss, System.Drawing.Imaging.ImageFormat.Jpeg);
var s = ss.ToArray();
var jpegQuality = 50;
Image image;
using (var inputStream = new MemoryStream(s))
{
image = Image.FromStream(inputStream);
var jpegEncoder = System.Drawing.Imaging.ImageCodecInfo.GetImageDecoders()
.First(c => c.FormatID == System.Drawing.Imaging.ImageFormat.Jpeg.Guid);
var encoderParameters = new System.Drawing.Imaging.EncoderParameters(1);
encoderParameters.Param[0] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, jpegQuality);
Byte[] outputBytes;
using (var outputStream = new MemoryStream())
{
image.Save(outputStream, jpegEncoder, encoderParameters);
return outputBytes = outputStream.ToArray();
}
}
}
}
Byte to bitmap ->
public BitmapImage ConvertBinaryToImage(byte[] array)
{
var image = new BitmapImage();
using (var ms = new MemoryStream(array))
{
image.BeginInit();
image.CacheOption = BitmapCacheOption.OnLoad; // here
image.StreamSource = ms;
image.EndInit();
image.Freeze();
}
return image;
}
When I open the WindowDragAndDrop it loads all the images
But when I close it it still uses the same amount of memory
Image is indeed disposable (https://learn.microsoft.com/en-us/dotnet/api/system.drawing.image?view=netframework-4.8), so you also need:
using (var image = Image.FromStream(inputStream)){
}
Around everywhere you use Image objects.
The Goal:
I want to convert an ImageBrush to a byte[].
Why?:
Because I want to print out the image, but I can't create any UI elements besides something like a MessageBox. SO I found an online tool that takes in a byte array and produces an image.
How do I do this in C# (WPF)?
What I've tried so far:
I have already converted the ImageBrush to a BitmapSource as so:
BitmapSource src = (BitmapSource)imageBrush.ImageSource;
and have converted the BitmapSource to a Bitmap Image as so:
private BitmapImage BitmapSourceToBitmapImage(BitmapSource bmpSrc)
{
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
MemoryStream memoryStream = new MemoryStream();
BitmapImage bImg = new BitmapImage();
encoder.Frames.Add(BitmapFrame.Create(bmpSrc));
encoder.Save(memoryStream);
memoryStream.Position = 0;
bImg.BeginInit();
bImg.StreamSource = memoryStream;
bImg.EndInit();
memoryStream.Close();
return bImg;
}
But for the life of me I cannot get this BitmapImage to a byte array! I have tried this:
private byte[] BitmapImagetoByteArray(BitmapImage bitmapImage) {
byte[] data;
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapImage));
using(MemoryStream ms = new MemoryStream())
{
encoder.Save(ms);
data = ms.ToArray();
}
return data;
}
The Problem/Error:
But when the encoder tries to save the memory stream, it says a frame has been disposed... see error message below:
Void SaveFrame(System.Windows.Media.SafeMILHandle, System.Windows.Media.SafeMILHandle, System.Windows.Media.Imaging.BitmapFrame)
Cannot access a disposed object.
System.ObjectDisposedException: Cannot access a disposed object.
at System.Windows.Media.Imaging.BitmapEncoder.SaveFrame(SafeMILHandle frameEncodeHandle, SafeMILHandle encoderOptions, BitmapFrame frame)
at System.Windows.Media.Imaging.BitmapEncoder.Save(Stream stream)
Any help? How can I display the ImageBrush without creating UI elements!
The error was not to set BitmapCacheOption.OnLoad, which is necessary when the source stream is to be closed right after EndInit:
bImg.BeginInit();
bImg.CacheOption = BitmapCacheOption.OnLoad;
bImg.StreamSource = memoryStream;
bImg.EndInit();
memoryStream.Close();
However, creating the intermediate BitmapImage wasn't necessary at all. The code should simply look like this:
private byte[] BitmapSourceToByteArray(BitmapSource bmpSrc)
{
var encoder = new JpegBitmapEncoder();
encoder.QualityLevel = 100;
encoder.Frames.Add(BitmapFrame.Create(bmpSrc));
using (var stream = new MemoryStream())
{
encoder.Save(stream);
return stream.ToArray();
}
}
I have saved images in our database by using the following method to convert them to byte arrays in different ImageFormats:
public byte[] foo()
{
Image img = Image.FromFile(path);
var tmpStream = new MemoryStream();
ImageFormat format = img.RawFormat;
img.Save(tmpStream, format);
tmpStream.Seek(0, SeekOrigin.Begin);
var imgBytes = new byte[MAX_IMG_SIZE];
tmpStream.Read(imgBytes, 0, MAX_IMG_SIZE);
return imgBytes;
}
Now I need to read them out and convert them back into the BitmapImage type so I can display them to the user. I was thinking about using the Image.FromStream(Stream) method but that doesn't seem to take into account the different ImageFormats... Anyone know what to do? Thanks in advance.
You shouldn't use classes from the WinForms System.Drawing namespace in a WPF application (like you do with Image.FromFile).
WPF provides its own set of classes to load and save bitmaps from Streams and URIs, and has built-in support for automatically detecting the format of a bitmap frame buffer.
Just create a BitmapImage or a BitmapFrame directly from a Stream:
public static BitmapSource BitmaSourceFromByteArray(byte[] buffer)
{
var bitmap = new BitmapImage();
using (var stream = new MemoryStream(buffer))
{
bitmap.BeginInit();
bitmap.CacheOption = BitmapCacheOption.OnLoad;
bitmap.StreamSource = stream;
bitmap.EndInit();
}
bitmap.Freeze(); // optionally make it cross-thread accessible
return bitmap;
}
or
public static BitmapSource BitmaSourceFromByteArray(byte[] buffer)
{
using (var stream = new MemoryStream(buffer))
{
return BitmapFrame.Create(
stream, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
}
}
Either method returns a BitmapSource, which is the base class of BitmapImage and BitmapFrame, and should be sufficient to deal with bitmaps in the rest of your application. E.g. the Source property of an Image control uses another base class, ImageSource, as property type.
Note also that when you load a BitmapSource from a Stream that is to be closed after loading, you have to set BitmapCacheOption.OnLoad. Otherwise the Stream must be kept open until the bitmap is eventually shown.
For encoding a BitmapSource you should be using a method like this:
public static byte[] BitmapSourceToByteArray(BitmapSource bitmap)
{
var encoder = new PngBitmapEncoder(); // or any other BitmapEncoder
encoder.Frames.Add(BitmapFrame.Create(bitmap));
using (var stream = new MemoryStream())
{
encoder.Save(stream);
return stream.ToArray();
}
}
Hi I wanna convert binary array to bitmap and show image in a picturebox. I wrote the following code but I got exception that says that the parameter is not valid .
public static Bitmap ByteToImage(byte[] blob)
{
MemoryStream mStream = new MemoryStream();
byte[] pData = blob;
mStream.Write(pData, 0, Convert.ToInt32(pData.Length));
Bitmap bm = new Bitmap(mStream);
mStream.Dispose();
return bm;
}
It really depends on what is in blob. Is it a valid bitmap format (like PNG, BMP, GIF, etc?). If it is raw byte information about the pixels in the bitmap, you can not do it like that.
It may help to rewind the stream to the beginning using mStream.Seek(0, SeekOrigin.Begin) before the line Bitmap bm = new Bitmap(mStream);.
public static Bitmap ByteToImage(byte[] blob)
{
using (MemoryStream mStream = new MemoryStream())
{
mStream.Write(blob, 0, blob.Length);
mStream.Seek(0, SeekOrigin.Begin);
Bitmap bm = new Bitmap(mStream);
return bm;
}
}
Don't dispose of the MemoryStream. It now belongs to the image object and will be disposed when you dispose the image.
Also consider doing it like this
var ms = new MemoryStream(blob);
var img = Image.FromStream(ms);
.....
img.Dispose(); //once you are done with the image.
System.IO.MemoryStream mStrm = new System.IO.MemoryStream(your byte array);
Image im = Image.FromStream(mStrm);
im.Save("image.bmp");
Try this. If you still get any error or exception; please post your bytes which you are trying to convert to image. There should be problem in your image stream....
I have the following code:
MemoryStream imageStream;
public ImageVideoFrame(BitmapSource frame)
{
imageStream = new MemoryStream();
BitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(frame));
encoder.Save(imageStream);
imageStream.Seek(0, SeekOrigin.Begin);
}
public BitmapSource Frame
{
BitmapDecoder decoder = new PngBitmapDecoder(image,
BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
BitmapSource bitmapSource = decoder.Frames.First();
return bitmapSource;
}
used to compress images in memory to reduce memory usage. The problem with the above code is that I get a NotSupportedExcpetion Constructing the PngBitmapDecoder. When debugging the position of the imageStream is shown to be